Gardeners often "naturalize" their plantings to create a look of informal spontaneity. Planting bulbs to naturalize in your lawn is an easy way to put on a great display of spring color. However, while planting the bulbs is easy, there are a few things to consider when planning and caring for bulbs planted in a lawn.
Choosing Bulbs to Plant
Remember that you will be planting flowers in your lawn, which means that you'll need to maintain both the flowers and the lawn. This can be a bit tricky unless you select your bulbs based on these recommendations.
- Early risers: Select bulbs that germinate and bloom in very early spring, so they will be done blooming and the leaves are starting to fade by the time to start mowing.
- Naturalizers (perennializing): Choose bulbs that will live and spread for many years, so you don’t have to plant them every fall. Look for the words "naturalize" or "perennialize" in their description.
- Lesser grades (smaller bulbs): This is one time you don’t need the biggest, most expensive grade bulb. A swath of small bulbs will put on a good show and will have time to mature and spread in your lawn.
While you can experiment with any early-blooming bulb, these are most likely to combine beauty and convenience in your lawn:
- Iris danfordiae (Dwarf Iris)
- Iris reticulata
- Muscari (Grape hyacinth)
- Small daffodils
- Wood anemone (Anemone nemorosa)
Many catalogs now list bulbs specifically for naturalizing.
Where to Plant
Don’t plant bulbs in poor lawns or lawns that require and/or receive a lot of maintenance. In a poor site, the bulbs won’t be able to compete with the grass for limited fertility and water.
In a highly maintained lawn, the excessive nitrogen fertilizer and water and the use of weed killers or pesticides are not good conditions for dormant bulbs.
Bulbs will do best in lawns that can provide the same conditions bulbs as a flower bed:
- Good drainage (dormant bulbs in wet soil will rot)
- Fertile soil with organic matter
- Limited compaction
- Six or more hours of sun (at least in the spring, while they’re growing and blooming)
- About 1 inch of water per week
- Limited foot traffic
Planting in a lawn is different from planting in a garden bed. These tips will help you ensure the health of both the bulbs and your grass:
- Bulbs can be planted closer than you would normally space them in a garden, but they should be planted a bit deeper; generally, plant them four times the height of the bulbs. For example, a 1-inch bulb should be planted four inches deep.
- If you are planting a large number of bulbs, it is easier to slice into the lawn, as if you were lifting sod. Roll the sod out of the way, place the bulbs and roll the sod back into place.
- Apply bulb fertilizer per package directions. You can add it to each individual planting hole, but it is much easier to simply broadcast the fertilizer over the planting area.
- To make your bulbs look like they spread naturally, grab a handful and let them drop from about waist height. Plant them where they land.
It's not difficult to care for naturalized bulbs, but it's important to remember to care for the bulbs at the same time that you tend to the lawn.
- Water your bulbs regularly (at least 1 inch per week) after planting.
- If you fertilize your lawn with a turf fertilizer, supplement the area with a bulb fertilizer. Lawn fertilizers are high in nitrogen, which is great for leaves, but the bulbs will need more phosphorous and potassium to keep going and bloom again.
- You should not need to deadhead the flower stalks in the spring, after blooming. Bulbs labeled as good naturalizers can take care of themselves.
When to Mow
Mowing can be tricky, especially if you happen to have a wet spring and a lush lawn. Even if the flowers stand only a few inches high, the foliage that persists will often shoot up several inches after flowering. To keep your bulbs thriving, you need to allow the foliage to yellow and begin to die back, before mowing. This usually takes up to a month, for small bulbs.
Some bulbs, like Muscari, will send up a second flush of growth in the fall. Again, you should allow this growth to die back normally before mowing if you want the bulbs to store enough energy to bloom again next spring.
Plant in swaths or clusters so that you can mow around the whole area. It will still look a bit untidy, but at least it will look intentional. For the last mowing in the fall, set the mower on its lowest setting. This will not only buy you a week or two before you need to mow in the spring, but it will also allow more sun and heat to reach the bulbs.